{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89605", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.733Z", "datePublished": "2026-09-11T19:45:08.101Z", "dateUpdated": "2026-10-19T08:49:36.445Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:49:36.445Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\necryptfs: release message context on send failure\n\necryptfs_send_message_locked() moves a message context from the free\nlist to the allocated list before sending the request to the userspace\ndaemon.\n\nIf ecryptfs_send_miscdev() fails, the context is left on the\nallocated list and cannot be reused. Move it back to the free list on\nfailure and clear the caller's pointer." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bug is reached only via local syscalls: open/creat on an eCryptfs mount drives pki_encrypt_session_key()/decrypt_pki_encrypted_session_key() into ecryptfs_send_message_locked(), and the per-euid daemon is registered with open(/dev/ecryptfs); no network or adjacent protocol path exists.\nAC:L - ecryptfs_send_miscdev() fails only on kmalloc(), which a local attacker in a memory cgroup can force by filling memory.max so the small GFP_KERNEL allocation returns NULL; the attacker then repeats create/open while running the daemon, with no race or other condition outside their control.\nPR:L - Neither miscdev_open() nor the PKI send path checks capabilities. An unprivileged user reaches this by running ecryptfsd on /dev/ecryptfs and using an eCryptfs mount from setuid mount.ecryptfs_private or an existing encrypted home, with a user-keyring PRIVATE_KEY auth token.\nUI:N - The attacker registers their own daemon, installs their own auth token, uses their own eCryptfs directory, and issues the create/open syscalls; no other user needs to mount, open a file, or otherwise interact.\nS:U - The leaked msg_ctx slots and any later use of the dangling msg_ctx->task pointer stay inside the host kernel's eCryptfs messaging subsystem; this is ordinary kernel impact, not a VM, IOMMU, or sandbox escape.\nC:H - A failed send leaves the msg_ctx PENDING with a raw task_struct pointer. After the sender exits, the attacker's daemon can write a MSG_RESPONSE with that index and predictable counter so ecryptfs_process_response() calls wake_up_process() on the freed task, a UAF that discloses kernel memory.\nI:H - The same task_struct use-after-free is heap-sprayable: wake_up_process() writes into a recycled task object and can hijack control flow. Stuck PENDING contexts are also never returned to the 32-slot global pool, breaking eCryptfs messaging for every user.\nA:H - Each failed send permanently removes one of 32 global msg_ctx slots from the free list until reboot, fully denying eCryptfs PKI wrap/unwrap for all users, and the dangling-task wake_up_process() path can oops or panic the kernel." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ecryptfs/messaging.c" ], "versions": [ { "version": "f66e883eb6186bc43a79581b67aff7d1a69d0ff1", "lessThan": "177e0c32fec3602bb3b64139bb8bb610cd6722c7", "status": "affected", "versionType": "git" }, { "version": "f66e883eb6186bc43a79581b67aff7d1a69d0ff1", "lessThan": "743e7aeb9575c0838d8996d40d81a6b8fa5cd060", "status": "affected", "versionType": "git" }, { "version": "f66e883eb6186bc43a79581b67aff7d1a69d0ff1", "lessThan": "590fc6140e29c54d2f7839eb9df78d106ee1905e", "status": "affected", "versionType": "git" }, { "version": "f66e883eb6186bc43a79581b67aff7d1a69d0ff1", "lessThan": "30845ed227475a11a49ccce047837d016b7e0f49", "status": "affected", "versionType": "git" }, { "version": "f66e883eb6186bc43a79581b67aff7d1a69d0ff1", "lessThan": "47ce611cb13f0eefa550d5434c1afcd4217bfc3e", "status": "affected", "versionType": "git" }, { "version": "f66e883eb6186bc43a79581b67aff7d1a69d0ff1", "lessThan": "9319706316a8e79f374627554386d575a84b637f", "status": "affected", "versionType": "git" }, { "version": "f66e883eb6186bc43a79581b67aff7d1a69d0ff1", "lessThan": "654b7e79443f5ea90849f5c1cf70c0d94bd5b10e", "status": "affected", "versionType": "git" }, { "version": "f66e883eb6186bc43a79581b67aff7d1a69d0ff1", "lessThan": "219644a3ad5518217b2d62cad6d2c36a2308c949", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ecryptfs/messaging.c" ], "versions": [ { "version": "2.6.26", "status": "affected" }, { "version": "0", "lessThan": "2.6.26", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.270", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.221", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.109", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.26", "versionEndExcluding": "5.10.270" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.26", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.26", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.26", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.26", "versionEndExcluding": "6.12.109" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.26", "versionEndExcluding": "6.18.50" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.26", "versionEndExcluding": "7.2.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.26", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/177e0c32fec3602bb3b64139bb8bb610cd6722c7" }, { "url": "https://git.kernel.org/stable/c/743e7aeb9575c0838d8996d40d81a6b8fa5cd060" }, { "url": "https://git.kernel.org/stable/c/590fc6140e29c54d2f7839eb9df78d106ee1905e" }, { "url": "https://git.kernel.org/stable/c/30845ed227475a11a49ccce047837d016b7e0f49" }, { "url": "https://git.kernel.org/stable/c/47ce611cb13f0eefa550d5434c1afcd4217bfc3e" }, { "url": "https://git.kernel.org/stable/c/9319706316a8e79f374627554386d575a84b637f" }, { "url": "https://git.kernel.org/stable/c/654b7e79443f5ea90849f5c1cf70c0d94bd5b10e" }, { "url": "https://git.kernel.org/stable/c/219644a3ad5518217b2d62cad6d2c36a2308c949" } ], "title": "ecryptfs: release message context on send failure", "x_generator": { "engine": "bippy-1.2.0" } } } }